On 2013/9/14 8:19, John Stultz wrote: > Currently seqlocks and seqcounts don't support lockdep. > > After running across a seqcount related deadlock in the timekeeping > code, I used a less-refined and more focused varient of this patch > to narrow down the cause of the issue. > > This is a first-pass attempt to properly enable lockdep functionality > on seqlocks and seqcounts. > > Since seqcounts are used in the vdso gettimeofday code, I've provided > lockdep accessors. > > I've also handled one cases where there were nested seqlock writers > and there may be more edge cases. > > Comments and feedback would be appreciated! >
Could you describe how seqlocks/seqcounts can lead to deadlock in the changelog? > Cc: Mathieu Desnoyers <[email protected]> > Cc: Li Zefan <[email protected]> > Cc: Steven Rostedt <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Signed-off-by: John Stultz <[email protected]> > --- > v2: > * Update to new simplified lockdep.h > * vdso accessor simplifications > * removed needless preempt_disable > * removed unneeded ifdefs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
